The Grid Compass was invented in 1979 by William Moggridge, but the first laptop was invented by Alan Kay in 1983. By 1988 laptops actually had a screen, not just a graph.
By 1982 laptop were open to public.
The first laptop which was more comfortable to handle with a lighter battery was invented in 1983, the Epson HX 20.
In 1987, Zenith invented the Nec UltraLite.